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authorRich Felker <dalias@aerifal.cx>2012-04-24 18:07:59 -0400
committerRich Felker <dalias@aerifal.cx>2012-04-24 18:07:59 -0400
commit60872cf9c93687e771c1b8bc41bb006bdcdc2e45 (patch)
tree5a90330df6f08de109d0f4f58347dbec642cbff6 /src/ldso
parent848d30a1e5f75988be4b291a431713e78ae09f79 (diff)
downloadmusl-60872cf9c93687e771c1b8bc41bb006bdcdc2e45.tar.gz
musl-60872cf9c93687e771c1b8bc41bb006bdcdc2e45.tar.xz
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first attempt at enabling stack protector support
the code is written to pre-init the thread pointer in static linked
programs that pull in __stack_chk_fail or dynamic-linked programs that
lookup the symbol. no explicit canary is set; the canary will be
whatever happens to be in the thread structure at the offset gcc
hard-coded. this can be improved later.
Diffstat (limited to 'src/ldso')
-rw-r--r--src/ldso/dynlink.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 0533bbb2..d04bef62 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -59,9 +59,13 @@ struct dso
 	char buf[];
 };
 
+struct __pthread;
+struct __pthread *__pthread_self_init(void);
+
 static struct dso *head, *tail, *libc;
 static char *env_path, *sys_path, *r_path;
 static int rtld_used;
+static int ssp_used;
 static int runtime;
 static jmp_buf rtld_fail;
 static pthread_rwlock_t lock;
@@ -108,6 +112,7 @@ static void *find_sym(struct dso *dso, const char *s, int need_def)
 	void *def = 0;
 	if (h==0x6b366be && !strcmp(s, "dlopen")) rtld_used = 1;
 	if (h==0x6b3afd && !strcmp(s, "dlsym")) rtld_used = 1;
+	if (h==0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 	for (; dso; dso=dso->next) {
 		Sym *sym;
 		if (!dso->global) continue;
@@ -611,6 +616,8 @@ void *__dynlink(int argc, char **argv)
 		reclaim((void *)builtin_dsos, 0, sizeof builtin_dsos);
 	}
 
+	if (ssp_used) __pthread_self_init();
+
 	errno = 0;
 	return (void *)aux[AT_ENTRY];
 }